Re: [OctDev] bwlabeln "finished"

[Kris T. <kri...@gm...>]

Hi Jordi

My initial impression if your newest bwlabeln implementation seems good! It's not so easy to test this exhaustively of course. But for instance this works

tmp=ones(2,2,3);
% add another "blob" somewhere further away
tmp(3:4, 4:6, 2:3)=ones(2,3,2);
res=bwlabeln(tmp~=0);
% we should have found 2 blobs
expectedres=ones(2,2,3);
expectedres(3:4, 4:6, 2:3)=ones(2,3,2)*2;
assert(res, expectedres)

The test above is somewhat problematic, as bwlabeln could just as well have found the blobs in different order. I haven't bothered to come up with a better test code.

I have only 1 problem. In my matlab code, I normally pass a (double) array with 0,1 to bwlabeln. This doesn't work for your implementation:

bwlabeln(ones([2,2,3]))
error: bwlabeln: first input argument must be a 'logical' ND-array

I can fix this by converting to bools of course

bwlabeln(ones([2,2,3]~=0))

but for matlab compatibility, ideally bwlabeln would do that itself. The same holds for bwlabel by the way.

Thanks for this!

Kris
> -----Original Message-----
> From: jo...@gm... [mailto:jo...@gm...] On Behalf Of Jordi
> Gutiérrez Hermoso
> Sent: 05 September 2012 21:15
> To: Kris Thielemans
> Cc: Octave Forge List
> Subject: Re: [OctDev] bwlabeln "finished"
> 
> Just a heads up to everyone, I've improved the bwlabeln code a bit to
> make it faster. Please let me know how it works for you.
> 
> TIA,
> - Jordi G. H.